<!DOCTYPE html>
<html>
	<head>
		<meta charset="utf-8">
		<style>
			.parent {
				background-color: #ff0;
				/* border: 1px  solid   #000; */
				overflow: hidden;
			}
			.s1 {
				margin-top: 50px;
			}
		</style>
	</head>
	<body>
		<div class="parent">
			<div class="son s1">111</div>
			<div class="son">222</div>
			<div class="son">333</div>
		</div>
	</body>
</html>
